Just to add on to what the others are saying.
On your host machine, the one running qemu, you make a connection to your wireless network.
Since the host machine is using wifi network adapter, the guest machine will be given a virtual lan adapter which is using the wifi adapter on the host.
That is the way it normally works.
However, if you have some special purpose application where you are wanting to have the VM have direct access to the wifi adapter, you can do that by setting it up for PCI passthrough. However, that will block the host from having access to wifi which is why most people wouldn’t configure it this way.